Nonlinear Aeroelastic Scaling Optimization Of Wing

Experimental testing of the aeroelastic scaling model is an important task in the development of aircraft.For modern aircraft design,the high aspect ratio wing is a typical design.The high aspect ratio and large flexibility of this type of wing determine its obvious structural geometric nonlinearity.Large deformation can have a non-negligible effect on its aeroelastic properties.Therefore,designing a scaled model considering geometric nonlinearity corresponding to a high aspect ratio wing has become an important research.In this thesis,the ISIGHT,NASTRAN and MATLAB will be used to calculate flutter and to optimize the aeroelastic scaling model for a large aspect ratio wing.The program written in the DMAP language is based on the "quasi-modal" method to calculate the nonlinear model as the target model,using the traditional linear scaling method and the equivalent static load method.A scaled model is established by considering the geometric nonlinearity reduction method.The traditional linear scaling method directly matches the modal and static response by decoupling the mass and stiffness or coupling the mass and stiffness.The scaling method considering geometric nonlinearity is based on the equivalent static load method to match the nonlinear static deformation of the full-size target model to complete the stiffness optimization,and then matching modality completes the mass optimization.The results of the final example show that the scaled model considering the geometric nonlinearity based on the equivalent static load method is more representative of the nonlinear effect of the actual model under various flight conditions than the scaled model designed by the traditional linear method.At the same time,the characteristics of the scaled model designed by this method under different initial conditions are discussed.The results show that the scaled model designed in this way is still affected by the initial load conditions,and can not fully reflect the nonlinear characteristics of the target model under all different conditions.Selecting the appropriate load conditions and taking the part with the corresponding error to study the nonlinear characteristics of the actual model can make the research results more accurate.